Explosive assembly



e 2543,70 Ice Patented June 5, 1956 'nited St Patent coil as shown or multiple coils. Multiple coils may be voluted or adjacent turns may lie side by side, 2,748,700 Figure 3 illustrates an embdiment of the anchored loop portion of the connecting means. Here a bail is EXPLOSIVE ASSEMBLY 5 provided by attaching a half loop of ribbon of fabric Cyril J. Breza, Mickleton, and (Iharles H. Noren, Wood- 2 "Q of an 6XP10S1Ve cartr dge 4 by means of a bury, N. .L, assignors to E. I. du Pont de Nemours and fetalnlng The anchored ball y be Provided y Company, Wilmington, Del., a corporation of Delaware other means such as by adhesively fastening a loose strip over the ends of a cartridge or by an extension of the Apphcat'on November 1953 Sena] 395,075 10 outer walls of the cartridge in the form of a loop. Al-

6 Claims (CL 102 24 ternatively the cartridge may be enclosed in a bag or net which provides loops at either end. The bail may be a tape or ribbon of any material having sulficient strength. A fabric, such as cotton duck, or metal, plastic or the The present invention relates to an explosive assembly. like may be employed. A pressure sensitive tape is pre- More particularly, it concerns a column of connected exferred since in this structure other bonding means to the plosive cartridges. cartridge is unnecessary. Where the bail is bounded to In many types of blasting operations, the preferred the cartridge by a retaining strip, this may be of the presmethod of introducing the explosive cartridges into the sure sensitive type. Other adhesive may also be used blasting zone is in the form of a column. This involves to anchor the retaining strip. connecting a plurality of cartridges end to end. A num- Figure 4 illustrates the explosive assembly in column ber of connectors for this purpose are known, most of form positioned within a borehole 5 and supported by them being in the nature of a sleeve having internal lowering line 6. In this figure, the bail is a loose strip gripping means and being adapted to receive a cartridge at 7 fastened directly to the cartridge over its end. The either end. Such connectors form a rigid column and column is formed by pulling the bail of adjacently posiare satisfactory when deformable. When the explosive tioned cartridges into opposite helices of a connecting composition in the cartridge is not deformable however link. the gripping means of the sleeve type connector cannot The column thus formed is sufliciently flexible to persecure a good hold. Furthermore, the sleeve connectors mit loading into a rough or irregular borehole, and the are both expensive and bulky. cartridges are all maintained in a column form. In the It is an object of the present invention to provid an event one or more cartridges become temporarily wedged explosive assembly in column form wherein the connectin the borehole while cartridges above o tinu to be ing means can be used with n nf l xplo i lowered, the connection will not be lost since the bail cartridges. will flatten and will remain within the loops of the con- Another object is to provide an assembly involving a ecting link. It will be readily appreciated that the re- Plurality 0f cartridges connected and to end wherein the lease of one or more cartridges during loading introduces connecting device does not increase the diameter of the a hazard of premature explosion due to the uncontrolled column. drop, and also destroys the desired column formation.

These and other objects will become apparent in the As mentioned previously, the connecting link is prefcourse of the following specification and claims. erably fabricated from a metal wire. It must have suf- The foregoing object is achieved by providing a pluralficient strength to retain its shape under the predetermined ily of Substantially Cylindrical Cartridges joined end to load of the explosive column. The helices are angled end y connecting means Comprising a Cartridge anchored from the straight section to the extent necessary to prori n 1 0p joined y a Connecting link haying helical vide an opening of suflicient size for easy insertion of the or open loop ends. The helices are substantially parallel bail, Where a single loop is employed to form the helix, to each other. They lie in the same plane relative to the it end hould xt nd at le t to th starting point f Straight Section Of the connecting linky are p the straight section thereby slightly overlapping to prevent erably so wound that their ends lie on opposite sides of the bail from being dislodged if the column becomes the straight section. wedged. The connector will normally have a length of In order it) more fully describe this invention, reference from one to two inches, and the loop a diameter of about is made to the accompanying drawings in which: /2 inch. The connecting means described provides a Figure 1 represents a side view of the connector emmethod of obtaining a column of regularly spaced exployed in the present invention; plosive cartridges.

Figure 2 represents a top view of the connector illus- Many equivalent modifications will be apparent to those trated in Figure l; skilled in the art from a reading of the above descrip- Figure 3 represents an explosive cartridge with a bail lion Without degarture fmm the Inventive p attached; and What is claimed 15:

Figure 4 represents a column of explosive cartiridges l exploslve a ssembly g a In column connected in accordance with this invention and posia Plurahty 9 exploslve caftn ges end to end relatlon' 50 sh1p wherein the connecting means for at least two of tloned within a borehole.

said cartridges comprises a bail of a flexible material adhesively bonded to one end of each of said cartridges, and a wire connector having an open loop at each end of a straight portion, each loop containing one of said bails. 2. An assembly as claimed in claim 1 wherein said flexible bail comprises a length of cloth tape containing Figure l is a side representation of the connecting body 1 having helical ends which is used as the link in the connecting means. As can be seen from the drawing the helices lie in the same plane relative to the connecting body. A top view of the structure, shown in Figure 2,

shows that the helices are parallel to each other. In the a Pressure senstive adhesive preferred embodiment they terminate on opposlte slde 3 An assembly as claimed in Claim 1 wherein the end 0f the straight section separates the helices. of each loop of the ire connector are beyond the be- The material of construction of the connecting link is ginning f th t i h portion not critical. Wire, such as for instance 70 mil steel wire, 4. An explosive assembly consisting of a plurality of is preferred. The helices may be formed by a single substantially cylindrical explosive cartridges j0ll'l6d end 3 4 to end by connecting means comprising a cartridge helices lie on opposite sides of the straight section of the anchored ribbon loop joined by a connecting link having Connectlng linkhelical ends,

5. The structure of claim 4 wherein the helices are References Clted m the file of this patent substantially parallel and lie in the same plane relative UNITED STATES PATENTS to the straight section of the connecting link. 1,281,958 Higgins Oct. 15, 1918 6. The structure of claim 5 wherein the ends of the 1,807,819 Altgelt June 2, 1931 

1. AN EXPLOSIVE ASSEMBLY COMPRISING IN COLUMN FORM SHIP WHEREIN THE CONNECTING MEANS FOR AT LEAST TWO OF SAID CARTRIDGES COMPRISES A BAIL OF A FLEXIBLE MATERIAL ADHESIVELY BONDED TO ONE END OF EACH OF SAID CARTRIDGES, AND A WIRE CONNECTOR HAVING AN OPEN LOOP AT EACH END OF A STRAIGHT PORTION, EACH LOOP CONTAINING ONE OF SAID BAILS. 